1. Field of the Invention
Embodiments of the invention generally relate to measurement systems and methods. More particularly, embodiments of the invention relate to measurement systems and methods employing phase shifting analysis for dimension measurement.
1. Description of Related Art
Dimension measurement of an object is desirable to ensure that such an object is appropriately configured or shaped to achieve suitable properties, such as suitable tolerances to fit with other components properly.
There have been attempts to measure an object to determine if the object is properly machined to have desirable dimensions. For example, some existing coordinate measurement machines (CMM) are employed to measure dimensions of an object. However, the measurement of such an object on the coordinate measurement machines is typically performed offline. In order to measure sizes of the object, machining processes of the object need to be paused so that the object is assembled onto the coordinate measurement machines to perform the measurement.
After measurement, the machining processes of the object may be restarted based on measurement results. However, for a precision object, it is not practical to remove the object from a machine tool and then remount the object on the machine tool due to the errors associated with realigning the object on the machine tool. Generally, such measurement may be performed several times to machine the object with desirable dimensions, which results in a lower productivity, lower quality due to remounting of the object and is time consuming.
In some current applications, touch probes are employed to measure dimensions of an object. The touch probe does not measure the object directly, but rather uses the scales on the machine tool itself to make the measurement, with the touch probe providing a trigger used to take the measurement. The object can be left on the machine by using an on-machine touch probe so there is no loss in quality due to re-mounting of the object. Although such measurement increases the productivity since the object needs not to be detached from a machining device for measurement by the touch probes, it may be still time consuming due to a relatively long motion time of the touch probes on the object.
Therefore, there is a need for new and improved measurement systems and methods for measurement of dimensions of an object.